The present invention relates to an ultrasonic array transducer, and more particularly, to an ultrasonic array transducer for non-destructively inspecting a weld joint.
Welding is a common process for attaching one metal member to another. This process generally involves heating an interface between the items which are to be welded, thereby melting the interface into one joint or weld nugget. Because this process has its application in many different types of manufacturing, such as automobile manufacturing, inspection ensuring that the weld nugget meets certain quality standards is a must. Specifically, it is desirable to inspect the area, size and configuration of the weld nugget and to determine if any defects exist therein. Uninspected welds may result in weld failure after the welded item is sold or distributed to a final user.
Ideally, a weld is inspected either during or shortly after the welding process so that added inspection does not increase weld time, and to allow weld problems to be identified when they occur. Furthermore, non-destructive testing is preferred so that welded parts which pass inspection may still be sold or distributed to the end user after they have been tested.
Visual inspection systems have been employed in the weld environment for this purpose. Specifically, an individual, such as a quality control person, may gage the size of the weld nugget or destructively test a welded item to determine its internal characteristics.
While weld systems do provide a quantitative analysis of the size of the weld nugget, visual inspection has some drawbacks. First, because of the bright light and harsh conditions generated by welding, visual inspection of a weld cannot be performed during the welding process. Instead, the welded item must be inspected off line, adding more time and cost to manufacturing. Second, to properly inspect the weld for defects, the internal structure of the weld nugget must be observed. This, in many instances, requires the welded item to be destructively tested, rendering the welded item useless. Besides the increased cost associated with scrapping an item for the purpose of inspection, it is practically impossible to destructively test all items. As such, destructive testing results in a lower number of samples tested and increased cost to manufacturing.
Devices and methods developed to inspect welds and other obscured items are generally disclosed in U.S. Patent Applications entitled TRANSDUCER BUILT INTO AN ELECTRODE and MULTIEYED ACOUSTICAL MICROSCOPIC LENS SYSTEM, invented by Maev et al. and assigned to the assignee of the present application and hereby incorporated by reference. While these devices and methods do provide a means for analyzing welded joints, they do not provide the quantitative accuracy sometimes required by manufacturers.
In view of the above, it would be desirable to manufacture an ultrasonic array transducer which is able to non-destructively test a weld subject and which has a high degree of resolution.
It is therefore an object of the present invention to provide an ultrasonic array transducer able to non-destructively inspect a weld joint.
It is yet another object of the present invention to provide an ultrasonic array transducer which has a high density of acoustical sound generating units for increasing resolution.
In accordance with the broad teachings of this invention, an ultrasonic probe and method for making the same is provided which has an advantageous construction and method of assembly. The ultrasonic probe has a segmented ultrasonic transducer having a plurality of individual independent transducers, a plurality of piezoelectric transducers connected to a first end of a respective individual independent transducers, and a plurality of electrical connections electrically communicating each the piezoelectric transducer with a power source.
In another aspect of the present invention, the power source comprises a pulser-receiver in electrical communication with a multiplexer. The multiplexer, in turn, is in electrical communication with the plurality of piezoelectric transducers. The pulser-receiver is responsive to the multiplexer to provide a display representative of acoustical images received by the piezoelectric transducers.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.